I have a Wadia 850 with the Statement upgrade From GNSC. I have tried almost every powercord and interconnect I can think of from Audiquest,Cards,Jenna Labs,Kimber,Nordost and so on. I settled with Silent Source cables for powercord and interconnect on the 850.
I liked the Mappleshade Omega Mikro Planar IV Silver LCX interconnect the best by a very small margin over the Silent source but it was very fragile for were I had to use it,if my set up would have been different I would have keep Mappleshade. The Silent source cords are some of the best I personally have ever heard and at a very reasonable price. I would also go balanced IMHO. Not to change the cable question but you might also want to check with Steve Huntley at The Great Northern sound on possible upgrades to your 21.
Good Luck.